scholarly journals Expanding the Clinico-Genetic Spectrum of Myofibrillar Myopathy: Experience From a Chinese Neuromuscular Center

2020 ◽  
Vol 11 ◽  
Author(s):  
Yue-Bei Luo ◽  
Yuyao Peng ◽  
Yuling Lu ◽  
Qiuxiang Li ◽  
Huiqian Duan ◽  
...  
Keyword(s):  
Neuromuscular Disorders ◽  
Myofibrillar Myopathy ◽  
Pathogenic Variants ◽  
Correlation Spectrum ◽  
Genetic Features ◽  
Cardiac Evaluation ◽  
Αb Crystallin ◽  
Hereditary Myopathy ◽  
Related Proteins ◽  
First Time

Background: Myofibrillar myopathy is a group of hereditary neuromuscular disorders characterized by dissolution of myofibrils and abnormal intracellular accumulation of Z disc-related proteins. We aimed to characterize the clinical, physiological, pathohistological, and genetic features of Chinese myofibrillar myopathy patients from a single neuromuscular center.Methods: A total of 18 patients were enrolled. Demographic and clinical data were collected. Laboratory investigations, electromyography, and cardiac evaluation was performed. Routine and immunohistochemistry stainings against desmin, αB-crystallin, and BAG3 of muscle specimen were carried out. Finally, next-generation sequencing panel array for genes associated with hereditary neuromuscular disorders were performed.Results: Twelve pathogenic variants in DES, BAG3, FLNC, FHL1, and TTN were identified, of which seven were novel mutations. The novel DES c.1256C>T substitution is a high frequency mutation. The combined recessively/dominantly transmitted c.19993G>T and c.107545delG mutations in TTN gene cause a limb girdle muscular dystrophy phenotype with the classical myofibrillar myopathy histological changes.Conclusions: We report for the first time that hereditary myopathy with early respiratory failure patient can have peripheral nerve and severe spine involvement. The mutation in Ig-like domain 16 of FLNC is associated with the limb girdle type of filaminopathy, and the mutation in Ig-like domain 18 with distal myopathy type. These findings expand the phenotypic and genotypic correlation spectrum of myofibrillar myopathy.

scholarly journals Characterization of Chinese patients with myofibrillar myopathy from a single center: expanding the clinico-genetic spectrum

2019 ◽  
Author(s):  
Yue-Bei Luo ◽  
Yuyao Peng ◽  
Yuling Lu ◽  
Qiuxiang Li ◽  
Huiqian Duan ◽  
...  
Keyword(s):  
Neuromuscular Disorders ◽  
Chinese Patients ◽  
Myofibrillar Myopathy ◽  
Pathogenic Variants ◽  
Correlation Spectrum ◽  
Genetic Features ◽  
Cardiac Evaluation ◽  
Αb Crystallin ◽  
Hereditary Myopathy ◽  
Related Proteins

Abstract Background: Myofibrillar myopathy is a group of hereditary neuromuscular disorders characterized by dissolution of myofibrils and abnormal intracellular accumulation of Z disc-related proteins. We aimed to characterize the clinical, physiological, pathohistological and genetic features of Chinese myofibrillar myopathy patients from a single neuromuscular center.Methods: a total of 18 patients were enrolled. Demographic and clinical data were collected. Laboratory investigations, electromyography and cardiac evaluation was performed. Routine and immunohistochemistry stainings against desmin, αB-crystallin and BAG3 of muscle specimen were carried out. Finally, next-generation sequencing of genes associated with hereditary neuromuscular disorders were performed. Results: twelve pathogenic variants in DES, BAG3, FLNC, FHL1 and TTN were identified, of which 7 were novel mutations. The novel DES c.1256C>T substitution is a high frequency mutation. The combined recessively/dominantly transmitted c. 19993G>T and c. 107545delG mutations in TTN gene cause a limb girdle muscular dystrophy phenotype with the classical myofibrillar myopathy histological changes. Conclusions: we report for the first time that hereditary myopathy with early respiratory failure patient can have peripheral nerve and severe spine involvement. The mutation in Ig-like domain 16 of FLNC is associated with the limb girdle type of filaminopathy, and the mutation in Ig-like domain 18 with distal myopathy type. These findings expand the phenotypic and genotypic correlation spectrum of myofibrillar myopathy.

High efficiency and clinical relevance of exome sequencing in the daily practice of neurogenetics

2021 ◽  
pp. jmedgenet-2020-107369
Author(s):  
Quentin Thomas ◽  
Antonio Vitobello ◽  
Frederic Tran Mau-Them ◽  
Yannis Duffourd ◽  
Agnès Fromont ◽  
...  
Keyword(s):  
Exome Sequencing ◽  
Neurological Disorders ◽  
High Efficiency ◽  
Neuromuscular Disorders ◽  
Daily Practice ◽  
Pathogenic Variants ◽  
Complex Phenotypes ◽  
Cerebellar Ataxias ◽  
Mitochondrial Origin ◽  
Second Tier

ObjectiveTo assess the efficiency and relevance of clinical exome sequencing (cES) as a first-tier or second-tier test for the diagnosis of progressive neurological disorders in the daily practice of Neurology and Genetic Departments.MethodsSixty-seven probands with various progressive neurological disorders (cerebellar ataxias, neuromuscular disorders, spastic paraplegias, movement disorders and individuals with complex phenotypes labelled ‘other’) were recruited over a 4-year period regardless of their age, gender, familial history and clinical framework. Individuals could have had prior genetic tests as long as it was not cES. cES was performed in a proband-only (60/67) or trio (7/67) strategy depending on available samples and was analysed with an in-house pipeline including software for CNV and mitochondrial-DNA variant detection.ResultsIn 29/67 individuals, cES identified clearly pathogenic variants leading to a 43% positive yield. When performed as a first-tier test, cES identified pathogenic variants for 53% of individuals (10/19). Difficult cases were solved including double diagnoses within a kindred or identification of a neurodegeneration with brain iron accumulation in a patient with encephalopathy of suspected mitochondrial origin.ConclusionThis study shows that cES is a powerful tool for the daily practice of neurogenetics offering an efficient (43%) and appropriate approach for clinically and genetically complex and heterogeneous disorders.

scholarly journals Efficacy of BRAF and MEK Inhibition in Patients with BRAF-Mutant Advanced Melanoma and Germline CDKN2A Pathogenic Variants

Cancers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 2440
Author(s):  
Francesco Spagnolo ◽  
Bruna Dalmasso ◽  
Enrica Tanda ◽  
Miriam Potrony ◽  
Susana Puig ◽  
...  
Keyword(s):  
Real World ◽  
Response Rate ◽  
Suppressor Gene ◽  
Phase Iii ◽  
Clinical Activity ◽  
P Value ◽  
Pathogenic Variants ◽  
Phase Iii Trials ◽  
The Difference ◽  
First Time

Inherited pathogenic variants (PVs) in the CDKN2A tumor suppressor gene are among the strongest risk factors for cutaneous melanoma. Dysregulation of the p16/RB1 pathway may intrinsically limit the activity of MAPK-directed therapy due to the interplay between the two pathways. In our study, we assessed, for the first time, whether patients with germline CDKN2A PVs achieve suboptimal results with BRAF inhibitors (BRAFi)+/−MEK inhibitors (MEKi). We compared the response rate of nineteen CDKN2A PVs carriers who received first-line treatment with BRAFi+/−MEKi with an expected rate derived from phase III trials and “real-world” studies. We observed partial response in 16/19 patients (84%), and no complete responses. The overall response rate was higher than that expected from phase III trials (66%), although not statistically significant (p-value = 0.143; 95% CI = 0.60–0.97); the difference was statistically significant (p-value = 0.019; 95% CI = 0.62–0.97) in the comparison with real-world studies (57%). The clinical activity of BRAFi+/−MEKi in patients with germline CDKN2A PV was not inferior to that of clinical trials and real-world studies, which is of primary importance for clinical management and genetic counseling of this subgroup of patients.

Molecular genetic diagnostics of Bardet-Biedl syndrome with an MPS-panel

2021 ◽  
pp. 26-35
Author(s):  
М.Д. Орлова ◽  
П. Гундорова ◽  
А.В. Поляков
Keyword(s):  
Autosomal Recessive ◽  
Molecular Genetic ◽  
Autosomal Recessive Disorder ◽  
Genetic Diagnostics ◽  
Bardet Biedl Syndrome ◽  
Pathogenic Variants ◽  
Development Delay ◽  
Molecular Genetic Diagnostics ◽  
First Time

Синдром Барде-Бидля - аутосомно-рецессивное заболевание, характеризующееся ожирением, пигментной дегенерацией сетчатки, полидактилией, задержкой психоречевого развития и структурными повреждениями почек. В работе представлены результаты применения МПС-панели, включающей кодирующие последовательности и прилегающие интронные области 21 гена, ассоциированного с синдромом Барде-Бидля. Впервые была проведена молекулярно-генетическая диагностика в группе из сорока российских пациентов с синдромом Барде-Бидля из неродственных семей. В результате исследования удалось подтвердить диагноз молекулярно-генетическим методом у 40% пациентов (n=16). В генах BBS1, BBS7 и BBS10 встретились повторяющиеся варианты. Частота встречаемости патогенных и вероятно патогенных вариантов в генах BBS1 и BBS10 у российских пациентов соответствует зарубежным данным. Варианты в гене BBS7 встретились у пяти человек, у четырех из них был обнаружен патогенный вариант c.1967_1968delTAinsC, не встречающийся в других популяциях. Результаты, представленные в статье, показывают значительный вклад в заболеваемость синдромом Барде-Бидля в российской популяции патогенных вариантов в гене BBS7. Bardet-Biedl syndrome is an autosomal recessive disorder characterized by obesity, retinitis pigmentosa, polydactyly, development delay, and structural kidney defects. This study shows the results of using an MPS panel that includes coding sequences and intronic areas of 21 genes associated with Bardet-Biedl syndrome. For the first time molecular genetic testing has been provided for the group of 40 Russian patiens with Bardet-Biedl syndrome from unrelated families. As a result of the testing, diagnoses were confirmed for 40% of the patients (n=16). The genes BBS1, BBS7, BBS10 had recurrent variants. The frequency of pathogenic and likely pathogenic variants in the genes BBS1 and BBS10 among Russian patients matches the research data in other countries. Variants in the BBS7 gene were found for five people, four of them had a pathogenic variant c.1967_1968delTAinsC, which is not present among other populations. Results provided in this article show the significant role of pathogenic variants in the BBS7 gene in patients with Bardet-Biedl syndrome in Russian population.

scholarly journals A novel dominant D109A CRYAB mutation in a family with myofibrillar myopathy affects αB-crystallin structure

BBA Clinical ◽  
2017 ◽  
Vol 7 ◽  
pp. 1-7 ◽  
Author(s):  
Jakub P. Fichna ◽  
Anna Potulska-Chromik ◽  
Przemysław Miszta ◽  
Maria Jolanta Redowicz ◽  
Anna M. Kaminska ◽  
...  
Keyword(s):  
Myofibrillar Myopathy ◽  
Αb Crystallin

scholarly journals αIIbβ3 variants in ten families with autosomal dominant macrothrombocytopenia: Expanding the mutational and clinical spectrum

PLoS ONE ◽  
2020 ◽  
Vol 15 (12) ◽  
pp. e0235136
Author(s):  
Sara Morais ◽  
Jorge Oliveira ◽  
Catarina Lau ◽  
Mónica Pereira ◽  
Marta Gonçalves ◽  
...  
Keyword(s):  
Binding Sites ◽  
Autosomal Dominant ◽  
Transmembrane Domain ◽  
Laboratory Data ◽  
Atp Release ◽  
Cytoplasmic Domains ◽  
Pathogenic Variants ◽  
Distinct Disease ◽  
And Function ◽  
First Time

Background Rare pathogenic variants in either the ITGA2B or ITGB3 genes have been linked to autosomal dominant macrothrombocytopenia associated with abnormal platelet production and function, deserving the designation of Glanzmann Thrombasthenia-Like Syndrome (GTLS) or ITGA2B/ITGB3-related thrombocytopenia. Objectives To describe a series of patients with familial macrothrombocytopenia and decreased expression of αIIbβ3 integrin due to defects in the ITGA2B or ITGB3 genes. Methods We reviewed the clinical and laboratory records of 10 Portuguese families with GTLS (33 patients and 11 unaffected relatives), including the functional and genetic defects. Results Patients had absent to moderate bleeding, macrothrombocytopenia, low αIIbβ3 expression, impaired platelet aggregation/ATP release to physiological agonists and low expression of activation-induced binding sites on αIIbβ3 (PAC-1) and receptor-induced binding sites on its ligand (bound fibrinogen), upon stimulation with TRAP-6 and ADP. Evidence for constitutive αIIbβ3 activation, occurred in 2 out of 9 patients from 8 families studied, but also in 2 out of 12 healthy controls. We identified 7 missense variants: 3 in ITGA2B (5 families), and 4 in ITGB3 (5 families). Three variants (αIIb: p.Arg1026Trp and p.Arg1026Gln and β3: p.Asp749His) were previously reported. The remaining (αIIb: p.Gly1007Val and β3: p.Thr746Pro, p.His748Pro and p.Arg760Cys) are new, expanding the αIIbβ3 defects associated with GTLS. The integration of the clinical and laboratory data allowed the identification of two GTLS subgroups, with distinct disease severity. Conclusions Previously reported ITGA2B and ITGB3 variants related to thrombocytopenia were clustered in a confined region of the membrane-proximal cytoplasmic domains, the inner membrane clasp. For the first time, variants are reported at the outer membrane clasp, at the transmembrane domain of αIIb, and at the membrane distal cytoplasmic domains of β3. This is the largest single-center series of inherited macrothrombocytopenia associated with αIIbβ3 variants published to date.

scholarly journals Analysis of Genotype-Phenotype Correlations in Patients With Degenerative Dementia Through the Whole Exome Sequencing

2021 ◽  
Vol 13 ◽  
Author(s):  
Lin Sun ◽  
Jianye Zhang ◽  
Ning Su ◽  
Shaowei Zhang ◽  
Feng Yan ◽  
...  
Keyword(s):  
Exome Sequencing ◽  
Whole Exome Sequencing ◽  
Clinical Symptoms ◽  
Pathogenic Variants ◽  
Dementia Patients ◽  
Whole Exome ◽  
Uncertain Significance ◽  
Genetic Features ◽  
Standards And Guidelines ◽  
Degenerative Dementia

Background: Sporadic dementias generally occur in older age and are highly polygenic, which indicates some patients transmitted in a poly-genes hereditary fashion.Objective: Our study aimed to analyze the correlations of genetic features with clinical symptoms in patients with degenerative dementia.Methods: We recruited a group of 84 dementia patients and conducted the whole exome sequencing (WES). The data were analyzed focusing on 153 dementia-related causing and susceptible genes.Results: According to the American College of Medical Genetics and Genomics (ACMG) standards and guidelines, we identified four reported pathogenic variants, namely, PSEN1 c.A344G, APP c.G2149A, MAPT c.G1165A, and MAPT c.G742A, one reported likely pathogenic variant, namely, PSEN2 c.G100A, one novel pathogenic variants, SQSTM1 c.C671A, and three novel likely pathogenic variants, namely, ABCA7 c.C4690T, ATP13A2 c.3135delC, and NOS3 c.2897-2A > G. 21 variants with uncertain significance in PSEN2, C9orf72, NOTCH3, ABCA7, ERBB4, GRN, MPO, SETX, SORL1, NEFH, ADCM10, and SORL1, etc., were also detected in patients with Alzheimer’s disease (AD) and frontotemporal dementia (FTD).Conclusion: The new variants in dementia-related genes indicated heterogeneity in pathogenesis and phenotype of degenerative dementia. WES could serve as an efficient diagnostic tool for detecting intractable dementia.

Identification of two novel variants in GAA underlying infantile-onset Pompe disease in two Pakistani families

2020 ◽  
Vol 33 (4) ◽  
pp. 553-556
Author(s):  
Aman Ullah ◽  
Bibi Zubaida ◽  
Huma Arshad Cheema ◽  
Muhammad Naeem
Keyword(s):  
Pompe Disease ◽  
Age Of Onset ◽  
Pathogenic Variants ◽  
Whole Exome ◽  
Sequence Variations ◽  
Heterozygous Variant ◽  
Novel Variants ◽  
Carrier Identification ◽  
First Time ◽  
Pakistani Families

AbstractBackgroundPompe disease (PD) is an autosomal recessive metabolic myopathy with an average incidence of one in 40,000 live births. It has a variable age of onset and can be diagnosed within the first 3 months. Heart involvement and muscle weakness are its primary manifestations.Case presentationWe describe two families affected by PD with two rare, novel variants. To date, pathogenic variants in acid α-glucosidase (GAA) alone have accounted for all cases of the disease. Both families were screened for pathogenic sequence variations. This study presents the implications of regulatory or modifier sequences in the disease pathogenesis for the first time. A homozygous missense p.Arg854Gln variant in family A and a single heterozygous variant (p.Asn925His) in family B were found to be segregating according to the disease phenotype. The variants were not detected in our in-house database comprising 50 whole-exome sequences of healthy individuals from a local unrelated Pakistani population. In silico analyses predicted that the variants would have deleterious effects on the protein structure.ConclusionsThe variants likely underlie the infantile-onset PD (IOPD) in these Pakistani families. The study expands the mutation spectrum of GAA associated with IOPD and highlights the insufficiency of screening the GAA coding sequence to determine the cause of IOPD. The work should be helpful in carrier identification, improving genetic counselling, and prenatal diagnosis.

scholarly journals Fetal Anomalies Associated with Novel Pathogenic Variants in TMEM94

Genes ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 967
Author(s):  
Mohamed H. Al-Hamed ◽  
Nada Alsahan ◽  
Maha Tulbah ◽  
Wesam Kurdi ◽  
Wafa’a I. Ali ◽  
...  
Keyword(s):  
Developmental Disorder ◽  
Chromosomal Microarray ◽  
Global Developmental Delay ◽  
Facial Features ◽  
Chromosomal Microarray Analysis ◽  
Speech Delay ◽  
Loss Of Function ◽  
Pathogenic Variants ◽  
Antenatal Sonography ◽  
First Time

Background: Intellectual developmental disorder with cardiac defects and dysmorphic facies (IDDCDF, MIM 618316) is a newly described disorder. It is characterized by global developmental delay, intellectual disability and speech delay, congenital cardiac malformations, and dysmorphic facial features. Biallelic pathogenic variants of TMEM94 are associated with IDDCDF. Methods and Results: In a prenatal setting, where fetal abnormalities were detected using antenatal sonography, we used trio-exome sequencing (trio-ES) in conjunction with chromosomal microarray analysis (CMA) to identify two novel homozygous loss of function variants in the TMEM94 gene (c.606dupG and c.2729-2A>G) in two unrelated Saudi Arabian families. Conclusions: This study provides confirmation that TMEM94 variants may cause IDDCDF. For the first time we describe the pathogenicity of TMEM94 defects detected during the prenatal period.

scholarly journals The Dynamics of Postmitotic Reassembly of the Nucleolus

2000 ◽  
Vol 150 (3) ◽  
pp. 433-446 ◽  
Author(s):  
Miroslav Dundr ◽  
Tom Misteli ◽  
Mark O.J. Olson
Keyword(s):  
Fluorescence Recovery After Photobleaching ◽  
Fluorescent Protein ◽  
Living Cells ◽  
M Phase ◽  
Specific Proteins ◽  
Distribution Of Components ◽  
Green Fluorescent ◽  
Related Proteins ◽  
First Time ◽  
Rrna Sequences

Mammalian cell nucleoli disassemble at the onset of M-phase and reassemble during telophase. Recent studies showed that partially processed preribosomal RNA (pre-rRNA) is preserved in association with processing components in the perichromosomal regions (PRs) and in particles called nucleolus-derived foci (NDF) during mitosis. Here, the dynamics of nucleolar reassembly were examined for the first time in living cells expressing fusions of the processing-related proteins fibrillarin, nucleolin, or B23 with green fluorescent protein (GFP). During telophase the NDF disappeared with a concomitant appearance of material in the reforming nuclei. Prenucleolar bodies (PNBs) appeared in nuclei in early telophase and gradually disappeared as nucleoli formed, strongly suggesting the transfer of PNB components to newly forming nucleoli. Fluorescence recovery after photobleaching (FRAP) showed that fibrillarin-GFP reassociates with the NDF and PNBs at rapid and similar rates. The reentry of processing complexes into telophase nuclei is suggested by the presence of pre-rRNA sequences in PNBs. Entry of specific proteins into the nucleolus approximately correlated with the timing of processing events. The mitotically preserved processing complexes may be essential for regulating the distribution of components to reassembling daughter cell nucleoli.

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